I agree, but does it really matter that much?? I mean, Eminem was very cool when he still was pretty much underground, aggressive and not as mainstream fake-funny as he's trying to be now... according to a lot of more "serious" hiphop listeners. I don't know if it really matters when it comes to his music in general.

It's just an example of course, but I do like his older music a lot better than his newer almost mainstream orientated stuff... I don't think the same ever really happened to G'n R and Red Hot Chili Peppers though, so it depends a lot on the bands or artists themselves. Some seem to hardly be even influenced by their own success, others seem to sacrifice their uniqueness, style and so on just to earn even more money. The latter category artists usually quickly become uncool in my book.